MARUF, AFGHANISTAN
— If he is in Pakistan, as some suspect, Osama bin Laden should be safe from capture, as long as he stays off the main roads.

That, at least, was the first thing that came to mind, when I and four other journalists - two Pakistanis, an Australian, and an American - made our way into Afghanistan a few days ago, for a two-day visit.

Although Pakistan has deployed thousands of troops and set up 300 checkpoints along the 1,500-mile border to intercept fleeing Al Qaeda fighters, we encountered no Pakistan Army soldiers - only a handful of police checkpoints that let us pass with a wave of a flashlight.

It was an object lesson in what experts said all along. The Afghan-Pakistan border, with hundreds of smuggling routes over rugged mountain passes, is porous at best, despite concerted US, allied Afghan, and Pakistani efforts. With careful planning - and most important, the right contacts - anyone who wants to cross, Arab terrorist or American journalist, can do so.

There is some risk. Pakistani officials have taken more than 100 Arabs and other non-Afghans prisoner near Tora Bora, the fallen Al Qaeda stronghold. Dozens reportedly escaped yesterday after seizing weapons from their captors in the northwestern town of Parachinar, Pakistan. At least seven people were reported killed.

Our trip began farther south, in the village of Pishin, Pakistan, in the mud-walled home of Ahmedullah Alizai. As head of the small but influential Alizai tribe, he has been chosen as a minister in the interim Afghan government set to take office Saturday in Kabul.

His men would be our guides and guards along the 10-hour journey through Pakistan's tribal areas, across the mountain border, and finally to the Alizai stronghold, the Afghan town of Maruf in the far southeast corner of Kandahar Province.

In Pishin, our host was not Mr. Alizai, but his cherubic 10-year-old son, Mirwais. All but a few of the Alizai men had already journeyed to Maruf.

With unsettling maturity, Mirwais orders up a feast of spicy lamb, chicken kebabs, cauliflower, and flatbread. In a traditional Afghan guest room with pomegranate-colored carpets and cushions on the floor, we eat and plan the trip to Maruf. Departure time is set for 5 a.m. During dinner, Mirwais sits beneath a picture of his great-grandfather, a former minister in the Afghan government of the exiled king, Mohammad Zahir Shah.

Later that evening, we receive an unexpected visitor, a member of the Kakar tribe, a rival to the Alizais. Ostensibly, he's come to engage in the ancient ritual of gup-shup, or gossip, and to trade stories that make all the men laugh.

During the half-hour visit, he asks about the foreigners propping themselves on cushions in the room. The Alizais, trading nervous glances, say we are journalists from America who want to visit Afghanistan.

When the Kakar leaves, the Alizais hurriedly change our travel plans. The Kakars could cause problems, they say, and even lay an ambush to try to embarrass them.

It's an instant lesson in the often confusing world of Afghan tribal politics, a world of limited resources and long memories of past wrongs, where the guest-host relationship is a matter of deepest honor. (Taliban supreme leader Mullah Mohammad Omar refused US demands to hand over Mr. bin Laden, calling him a "guest.")

"I'll tell you a story about the Pashtun people," says Sohail, a Pashtun from the Northwest Frontier Province of Pakistan. Like many Afghans, he uses only one name. A guest is spending the night with a tribe in Afghanistan. A rival tribe learns of the visit, and decides to attack and kill the guest. The guest, understandably concerned, asks if he will be safe.

"Don't worry," his hosts assure. "If they kill you, then we will kill two of their guests."

After telling his tale, Sohail laughs. Somehow, I am not encouraged.

At 6:00 a.m. the next morning, we have been on the road for an hour, having left the highway long ago for the dusty, gravel roads that wind up into the mountains.

The early-morning hours are when border crossings are most open, according to the Alizais. Our first checkpost on the Pakistani side appears to be an afterthought. A policeman in baggy black trousers and long, black kameez shirt runs out of his concrete office into the road as our guide's car passes, and simply stares as our second vehicle, a four-wheel drive SUV, follows behind.

Then the policeman rubs his eyes and returns to his office.

As I usually do in Afghanistan, I am wearing a woolen Pakistani salwar kameez, the same baggy outfit worn in Afghanistan. One of my colleagues is wrapped in a blanket. We make no other attempt at disguise.

A few minutes later, our car stops. It is time for prayers, a ritual performed five times each day by devout Muslims. Our guides, six Afghan Alizais, wash their hands and feet in the cold waters of an irrigation ditch, lay out their prayer shawls, and bow toward the holy city of Mecca as the gray, gathering light of dawn stretches over the frigid valley.

The closer we get to the Afghan border, the harder the terrain and rougher the roads become. At the wheel of our car, a Pakistani journalist asks an elderly Alizai in the back seat if the roads in Afghanistan are like this.

"Nope," he says. "They are much worse."

At 8:45 a.m., we reach the last checkpost, on a ridge overlooking the Afghan border.

It's a square, one-room building built of concrete, manned by two Pakistani militiamen. They are both members of the Alizai tribe.

Worried about a potential ambush by their tribal rivals, or other problems, our Alizai guides decide to make a trial run to the checkpost before attempting to bring the second vehicle ahead.

After a few tense minutes, the car returns in a billowing cloud of Central Asian dust, and we drive through the checkpoint without pausing to wave.

"Gentlemen, congratulations," says Sohail. "We are in Afghanistan."

Next, our arrival in Maruf, Afghanistan, where the 12th and 21st centuries meet.